Electric-field effects on the diffusion of Si and Ge adatoms on Si(001) studied by density functional simulations
Electric-field effects on the diffusion of Si and Ge adatoms on Si(001) studied by density functional simulations
复制标题
通过密度泛函模拟研究电场对 Si 和 Ge 吸附原子在 Si(001) 上扩散的影响
DOI：
10.1103/physrevb.79.235430
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发表时间：
2009-06
影响因子：
3.7
通讯作者：
Che, J. G.
中科院分区：
文献类型：
--
作者：
He, Yao;Che, J. G.
我们提出了密度泛函理论 (DFT) 计算干净 Si(001) 表面上的电场效应以及 Si 或 Ge 吸附原子在 Si(001) 表面上扩散的结果。我们的结果表明，电场仅轻微影响干净Si(001)的二聚体键长和屈曲角度，这意味着扫描隧道显微镜尖端的电场不应负责观察对称二聚体和屈曲二聚体的翻转运动。此外，电场主要影响沿二聚体行的扩散，在正电场下扩散势垒可以大大降低。可以预期，正场应该使 Si 或 Ge 吸附原子在 Si(001) 表面上的扩散变得更加各向异性。
We present results of density functional theory (DFT) calculations of the electric-field effects on the clean Si(001) surface and the diffusion of Si or Ge adatoms on Si(001) surface. Our results indicate that the electric field only slightly affected the dimer bond lengths and buckling angles of the clean Si(001), implying that the electric field of scanning tunneling microscopy tip should not be responsible for the observation of symmetric dimers and the flip-flop motion of the buckling dimers. Also, the electric field mainly influences the diffusion along the dimer row, and the diffusion barrier could be reduced greatly under a positive electric field. It can be expected that the positive field should make the diffusion of Si or Ge adatoms on the Si(001) surface become more anisotropic.